Multi PSD-arrangement and circuitry

1. A light beam position detector, comprising: a detection window configured to enable detection of a position of striking light beam within the detection window, the detection window including: a first Position Sensitive Device (PSD) based on the lateral photoelectric effect, with two output signals that are dependent on the striking position of the light beam; an electronic readout circuitry for the first PSD; a second PSD based on the lateral photoelectric effect and aligned geometrically in line in succession with the first PSD, such that the first PSD and the second PSDs define the detection window.

2. The light beam position detector according to claim 1 , wherein: the first PSD and the second PSDs are electrically interconnected in series to form a linear sensor array.

3. The light beam position detector according to claim 1 , wherein: the electronic readout circuitry provides an alterable readout interconnection of the first PSD and of the second PSD.

4. The light beam position detector according to claim 1 , wherein: the readout circuitry is capable of switch between: an electrically concatenated series arrangement of the first PSD and the second PSDs, thereby electrically forming a single long PSD; and an electrically split series arrangement with at least the first PSD on one side and the second PSD on another side, by electrically forming the first PSD and the second PSD in a But-Cell arrangement, providing substantially centrically weighting of the light beam position along the detection window.

5. The light beam position detector according to claim 4 , wherein: the electrically formed single long PSD provides substantially linear weighting of the light beam position along the detection window; and the But-Cell arrangement provides substantially centrically weighting of the light beam position along the detection window.

6. The light beam position detector according to claim 4 , wherein the readout circuitry comprises: at least one active resonator circuit for an active backlight suppression which includes an operational amplifier, wherein: the active resonator circuit is connected to at least one of the first PSD and the second PSD and is configured to drain low frequency photo-induced currents from the connected PSD to ground; and each output of the first PSD and the second PSD is connected to at least one active resonator structure.

7. The light beam position detector according to claim 6 , wherein: the active resonator circuit is configured to provide a low impedance to an output of the first and second PSDs at low frequencies and higher impedance at high frequency, with an impedance below 1 kOhm at frequencies below 1 kHz and an impedance above 1 MegaOhm at a modulation frequency of the striking light beam intensity at the detector.

8. The light beam position detector according to claim 6 , wherein: the active resonator structure has an adjustable impedance-frequency characteristic enabled by at least one adjustable or switchable electrical component included in the active resonator structure, wherein an impedance of the active resonator structure at an upper and/or lower end of the impedance-frequency characteristic is adjustable.

9. The light beam position detector according to claim 4 , wherein: the readout circuitry is capable of being altered dependent on a diameter of the striking light beam in the detection window, from the concatenated series arrangement for light beam diameters smaller than one of the PSDs, to the split But-Cell arrangement for light beam diameters larger than one of the PSDs, according to an automatically determined intensity profile of the striking light beam in the detection window.

10. The light beam position detector according to claim 1 , wherein: the readout circuitry is configured to determine offset and/or amplification errors of analog signal processing channels of the readout circuit by transposing readout channels of the readout circuitry by alterable interconnections; and the channels include the active resonator structure.

11. A laser alignment system comprising: a laser projection device for emitting a laser plane; and a light beam position detector according to claim 1 , for determining a striking position of the laser plane in the detection window for a laser leveling application.

12. Electrical circuitry for evaluating an arrangement that includes the first PSD and the second PSD of the light beam position detector according to claim 1 , wherein the electrical circuitry: operates by a switchable readout interconnection of the first PSD and the second PSD in the readout circuitry of claim 1 ; and includes at least one active resonator structure that has at least one operational amplifier and is connected to at least one of the first PDS and the second PSD for suppressing low frequency saturation effects, with an adjustable impedance-frequency characteristic.

13. A method for light spot position determination on a laser receiver having at least two Position Sensitive Devices (PSDs), the method comprising: applying a light beam to an active surface of the PSDs, the laser beam having a modulated light intensity; generating at least two electrical signals dependent on the position of the light beam on the active surface according to the lateral photoelectric effect; and determining the position of the light beam according to the electrical signals by a readout circuit, including: evaluating a geometrical line arrangement of at least two PSD sensors, which form a detection window for the light spot; and adjusting a positional weighting characteristic of the position sensitivity of the geometrical line arrangement by altering interconnection of the at least two PSDs in the readout circuitry.

14. The method according to claim 13 , further comprising: altering the readout circuitry by switching the electrical interconnection of the PSDs between: an electrical series connection used for light spots smaller than the active surface of one of the PSDs; and a split But-Cell configuration in which the series arrangement is split in at least two separated parts with at least two electrically separated intermediate tappings, used for spot sizes larger than an active area of one of the PSDs.

15. The method according to claim 13 , further comprising: taping an electrical outlet of at least one of the PSDs by an active resonator circuit for suppressing low frequency saturation effects by draining current with frequencies below a modulation frequency of the light beam from the PDS; and providing higher load impedance at the modulation frequency of the light beam at least once at the electrical outputs of each of said at least two PSDs.

16. The method according to claim 15 , wherein taping the electrical outlet is performed by taping the electrical output with the active resonator providing low load impedance at low frequency.

17. The method according to claim 15 , further comprising: reconfiguring a positional weighting characteristic of the active resonator by adjusting electrical components of the active resonator by adjusting an impedance of the active resonator structure at an upper and/or lower end of a impedance-frequency characteristic of the active resonator.

18. A computer program product with program code being stored on a non-transitory machine readable medium, the program code being configured to automatically execute and operate the method according to claim 13 when the program code is executed at a digital computation unit of a laser levelling receiver.